This is wild, I mean, I think it is a bit over the top even for Google. Google is changing the background heading image for the Google search results based on your query. If you search for things like [creative ideas], [ideas for christmas], [flower ideas] and even others, Google will swap out the white background with an image background.
Here are more screen shots:
Google even shows love to SEOs with this:
This was first spotted by Yvo Schaap and shared with me on Twitter.
I can replicate this using Chrome mobile on my iPhone.
Forum discussion at Twitter.